Castor-oil, when good, is of a light amber or straw colour, inclining to a greenish cast. That which has the least smell, taste, and colour, is considered the mildest. The necessity of some attention to these signs may appear, when I state that I once took seven ounces of this oil in successive doses, and do verily believe that I might have continued to this present hour taking, daily, the usual dose furnished from the same quarter, with as little effect, had not my good genius directed me to send for an ounce from Apothecaries’ Hall. I recommend my readers to purchase their drugs, &c. in the same place. Ipecacuanha.—As this drug is sold to the public in a pulverized state, there is no short or off-hand test for discovering its purity. It is adulterated with emetic tartar. Opium.—Good opium in a concrete state should be of a blackish brown colour, of a strong fetid smell, a hard viscous texture, and heavy; and when rubbed between the finger and thumb, it is perfectly free from roughness or grittiness. This drug is liable to great adulteration, being frequently vitiated with cow-dung, or a powder composed of the dry leaves and stalks of the poppy, the gum of the mimosa, meal and other substances. The flavour alone indicates the goodness of opium in a liquid state. Rhubarb.—The marks of the goodness of rhubarb are the liveliness of its colour when cut; its being firm, dry, and solid, but not flinty or hard; its being easily pulverizable, and appearing, when powdered, of a fine bright yellow colour; and its imparting to the spittle, when chewed, a deep saffron-colour, and not proving slimy or mucilaginous to the taste. When rhubarb has become worm-eaten, druggist-ingenuity is called into play, by filling up the holes with a paste made of rhubarb-powder and mucilage; and then the physic-artists roll the mended pieces in the finest rhubarb powder to give their handy works a good colour and an appearance of freshness. Senna leaves are frequently mixed and sophisticated with leaves of argol, box leaves, &c. But among the frauds and impositions practised on the public, none are more odious and unprincipled, and, at the same time, more loudly call for the prompt and active interference of the Legislature, than the tricks and effrontery of impostors, quacks, and empirics in medicine, both regular and irregular. It cannot but have been the frequent subject of regret to every honest and reflecting person that this vile trade should receive A LEGAL SANCTION AND PROTECTION, which it most assuredly does by virtue of the stamp duty imposed on the villainous trash; and it cannot be sufficiently deplored that any government should find itself reduced to straits so deplorable, or be so short-sighted in its views of enlightened policy, as to be under the necessity of extracting a paltry and disgraceful profit to the revenue of the state, from the tolerance and encouragement of ignorance, imposture, and mischief.